src/govpn/cmd/govpn-client/main.go

   1 /*
   2 GoVPN -- simple secure free software virtual private network daemon
   3 Copyright (C) 2014-2015 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, either version 3 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 // Simple secure free software virtual private network daemon client.
  20 package main
  21
  22 import (
  23         "flag"
  24         "log"
  25         "net"
  26         "os"
  27         "os/signal"
  28         "time"
  29
  30         "govpn"
  31 )
  32
  33 var (
  34         remoteAddr = flag.String("remote", "", "Remote server address")
  35         proto      = flag.String("proto", "udp", "Protocol to use: udp or tcp")
  36         ifaceName  = flag.String("iface", "tap0", "TAP network interface")
  37         IDRaw      = flag.String("id", "", "Client identification")
  38         keyPath    = flag.String("key", "", "Path to passphrase file")
  39         upPath     = flag.String("up", "", "Path to up-script")
  40         downPath   = flag.String("down", "", "Path to down-script")
  41         stats      = flag.String("stats", "", "Enable stats retrieving on host:port")
  42         proxyAddr  = flag.String("proxy", "", "Use HTTP proxy on host:port")
  43         proxyAuth  = flag.String("proxy-auth", "", "user:password Basic proxy auth")
  44         mtu        = flag.Int("mtu", 1452, "MTU for outgoing packets")
  45         timeoutP   = flag.Int("timeout", 60, "Timeout seconds")
  46         noisy      = flag.Bool("noise", false, "Enable noise appending")
  47         cpr        = flag.Int("cpr", 0, "Enable constant KiB/sec out traffic rate")
  48         egdPath    = flag.String("egd", "", "Optional path to EGD socket")
  49 )
  50
  51 func main() {
  52         flag.Parse()
  53         timeout := *timeoutP
  54         var err error
  55         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  56
  57         govpn.MTU = *mtu
  58
  59         id, err := govpn.IDDecode(*IDRaw)
  60         if err != nil {
  61                 log.Fatalln(err)
  62         }
  63
  64         if *egdPath != "" {
  65                 log.Println("Using", *egdPath, "EGD")
  66                 govpn.EGDInit(*egdPath)
  67         }
  68
  69         pub, priv := govpn.NewVerifier(id, govpn.StringFromFile(*keyPath))
  70         conf := &govpn.PeerConf{
  71                 Id:          id,
  72                 Timeout:     time.Second * time.Duration(timeout),
  73                 NoiseEnable: *noisy,
  74                 CPR:         *cpr,
  75                 DSAPub:      pub,
  76                 DSAPriv:     priv,
  77         }
  78         govpn.PeersInitDummy(id, conf)
  79
  80         var conn govpn.RemoteConn
  81         var sink chan []byte
  82         var ready chan struct{}
  83         switch *proto {
  84         case "udp":
  85                 conn, sink, ready = startUDP()
  86         case "tcp":
  87                 if *proxyAddr != "" {
  88                         conn, sink, ready = proxyTCP()
  89                 } else {
  90                         conn, sink, ready = startTCP()
  91                 }
  92         default:
  93                 log.Fatalln("Unknown protocol specified")
  94         }
  95
  96         tap, ethSink, ethReady, _, err := govpn.TAPListen(
  97                 *ifaceName,
  98                 time.Second*time.Duration(timeout),
  99                 *cpr,
 100         )
 101         if err != nil {
 102                 log.Fatalln("Can not listen on TAP interface:", err)
 103         }
 104
 105         timeouts := 0
 106         firstUpCall := true
 107         var peer *govpn.Peer
 108         var ethPkt []byte
 109         var pkt []byte
 110         knownPeers := govpn.KnownPeers(map[string]**govpn.Peer{*remoteAddr: &peer})
 111
 112         log.Println(govpn.VersionGet())
 113         log.Println("Connected to", *proto, *remoteAddr)
 114         log.Println("Max MTU on TAP interface:", govpn.TAPMaxMTU())
 115         if *stats != "" {
 116                 log.Println("Stats are going to listen on", *stats)
 117                 statsPort, err := net.Listen("tcp", *stats)
 118                 if err != nil {
 119                         log.Fatalln("Can not listen on stats port:", err)
 120                 }
 121                 go govpn.StatsProcessor(statsPort, &knownPeers)
 122         }
 123
 124         termSignal := make(chan os.Signal, 1)
 125         signal.Notify(termSignal, os.Interrupt, os.Kill)
 126
 127         log.Println("Starting handshake")
 128         handshake := govpn.HandshakeStart(*remoteAddr, conn, conf)
 129
 130 MainCycle:
 131         for {
 132                 if peer != nil && (peer.BytesIn+peer.BytesOut) > govpn.MaxBytesPerKey {
 133                         peer.Zero()
 134                         peer = nil
 135                         handshake = govpn.HandshakeStart(*remoteAddr, conn, conf)
 136                         log.Println("Rehandshaking")
 137                 }
 138                 select {
 139                 case <-termSignal:
 140                         break MainCycle
 141                 case ethPkt = <-ethSink:
 142                         if peer == nil {
 143                                 if len(ethPkt) > 0 {
 144                                         ethReady <- struct{}{}
 145                                 }
 146                                 continue
 147                         }
 148                         peer.EthProcess(ethPkt, ethReady)
 149                 case pkt = <-sink:
 150                         timeouts++
 151                         if timeouts >= timeout {
 152                                 break MainCycle
 153                         }
 154                         if pkt == nil {
 155                                 ready <- struct{}{}
 156                                 continue
 157                         }
 158
 159                         if peer == nil {
 160                                 if govpn.IDsCache.Find(pkt) == nil {
 161                                         log.Println("Invalid identity in handshake packet")
 162                                         ready <- struct{}{}
 163                                         continue
 164                                 }
 165                                 if p := handshake.Client(pkt); p != nil {
 166                                         log.Println("Handshake completed")
 167                                         if firstUpCall {
 168                                                 go govpn.ScriptCall(*upPath, *ifaceName)
 169                                                 firstUpCall = false
 170                                         }
 171                                         peer = p
 172                                         handshake.Zero()
 173                                         handshake = nil
 174                                 }
 175                                 ready <- struct{}{}
 176                                 continue
 177                         }
 178                         if peer == nil {
 179                                 ready <- struct{}{}
 180                                 continue
 181                         }
 182                         if peer.PktProcess(pkt, tap, ready) {
 183                                 timeouts = 0
 184                         }
 185                 }
 186         }
 187         govpn.ScriptCall(*downPath, *ifaceName)
 188 }